Participants in this study will be asked to participate in a standard blood donation. The blood will be processed per standards at the investigators regional blood center (New York Blood Center) and then split into two equal units and shipped to Columbia University Medical Center for storage and transfusion. One unit will be transfused back into the same individual fresh (i.e. between 3-7 days after donation). The other unit will be transfused 42 days after donation. Blood samples will be drawn before, during, and after transfusion to measure levels of various analytes.